Tool/software:
Does the TCA9555 have automatic button debouncing built in? If it does, then is that true for both polled and interrupt?
Hi Tyrique,
You can search for debounce circuitry examples on the web if you need more ideas.
I believe a simple debounce can be as simple as a pull-up resistor, switch to GND, and capacitor.
See my drawing snippet:
The example in purple is without the capacitor. I think debounce is simply a lowpass filter.
IF you need a keypad scanner that has built in debounce with a clocking mechanism, you could consider using the TCA8418E keypad scanner. IT has built in registers to enable debouncing for keystroke inputs. The debounce works by clocking the input twice. It clocks once every 50us. If on the 2nd clock cycle the input is the same logic, only then will an interrupt occur.
Regards,
Tyler
